Oem Xenon problem 328ci 2000 e46

[also111]

I posted a month of so ago about this problem. I thought I fixed (change bulb 250$ each)it but it cam back second later Bmw told me that the Xenon are independant so i conclude that can be somewhere else in the car (wires..resistor......) . Probably never fixed it.
At times while the car is running, both xenons will turn off for a split second similtainiosly, then re-ignite. Can be parked of driving. Bumbs don't do it, just random. Took it to the dealer yesterday for regular service, and had them look at it. To my suprise(not), they couldn't find anything wrong. On the hour drive there, it never happend. The 10 mile drive home from work the other day was so bad, I turned the xenons off and just drove with fogs(was getting light out). I am guessing the light control module or the switch itself. Since they are turning off and on together, I am figuring it's farther up-stream than the ballast or bulbs. No other lights flicker. I have factory xenons, and have added DDE's (2yrs ago). Other than that, all factory stuff. Also, if anyone thinks I might be right, does anybody have the part #'s and know of a good place to order other than dealer? Sorry this is so long, but lots of details to put in to cut down on questions later.Thanks Yan

[cloak]

This describes my problem exactly. Seems to occur more when its cold out or when my car first starts. Anyone? I've been getting a tailight waring on the dash but it usually goes away in a min or 2. I've searched and read a post about a taillight bulb having something to do with it....??? I'm lost